Electronic switching device preferably operating contactlessly

摘要

The switching device (1) has a presence indicator (10) which can be influenced from the outside, a switching amplifier (11) following the presence indicator (10), an electronic switch (12) which can be controlled by the presence indicator (10) via the switching amplifier (11), and a feed circuit (13) for representing the feed voltage for the presence indicator (10) and for the switching amplifier (11), in which the switching amplifier (11) exhibits an output stage with a drive transistor and an output transistor following the drive transistor. The invention ensures that the output transistor of the output stage of the switching amplifier (11) always only consumes the required drive current due to the fact that the output transistor is associated with an auxiliary transistor, an auxiliary resistor and a voltage-increasing element and that the collector of the auxiliary transistor is driven by the drive transistor, the auxiliary resistor is connected, on the one hand, to the emitter of the auxiliary transistor and, on the other hand, to the base of the output transistor and the voltage-increasing element is connected, on the one hand, to the base of the auxiliary transistor and, on the other hand, to the collector of the output transistor. <IMAGE>